Micromirror with electrostatically controlled microshutter, matrix of micromirrors and infrared spectrophotometer comprising said matrix
An optic device with a variable operating mode comprises a micromirror which can be obscured by means of an electrostatically controlled microshutter. In the operating condition of the microshutter, the petal of this adheres over a substrate to allow a beam of light to reach the mirror. In the condition at rest, the petal is curled up and one of its surfaces receives the beam of light and reflects it in all directions, at the same time preventing this from reaching the mirror.
Latest C.R.F. Societa Consortile per Azioni Patents:
- Multi-cylinder internal combustion engine, with cylinders equipped with intake valve variable actuation systems having hydraulic circuits which cross each other
- System for assisting an operator in a work station
- Motor-vehicle driving assistance in low meteorological visibility conditions, in particular with fog
- MULTI-CYLINDER INTERNAL COMBUSTION ENGINE, WITH CYLINDERS EQUIPPED WITH INTAKE VALVE VARIABLE ACTUATION SYSTEMS HAVING HYDRAULIC CIRCUITS WHICH CROSS EACH OTHER
- Vehicle having a frame provided with a supporting structure for auxiliary units, in particular gas tanks or electric batteries
1. Field of the Invention
The present invention relates to electrostatically controlled optic devices with a variable operating mode, of the type comprising:
-
- a fixed support including a substrate in the form of a lamina a few millimeters or centimeters thick,
- an electrode composed of a film of electrically conductive material a few tens or hundreds of nanometers thick, applied to one side of the lamina constituting the substrate,
- a dielectric or ferroelectric insulating film with a thickness ranging from 0.1 micrometers to a few tens of micrometers, applied over the film constituting said electrode, and
- a movable petal, comprising a film of electrically conductive material, with a thickness ranging from a few fractions of micron to a few microns, having only an end portion connected rigidly to said insulating film and designed to assume an operating condition, in which it adheres completely with one of its surfaces, through electrostaticity, over said insulating film when an electric voltage is applied between said electrode and said petal, and a condition at rest, curled up, towards which the petal is drawn by its own elasticity when no electric voltage is applied, and in which a predominant portion of the aforesaid surface of the petal is spaced from said insulating film.
2. Background Art
A device of this type was proposed for example in the European patent application EP-A-1 008 885 by the same Applicant.
SUMMARY OF THE INVENTIONThe object of the present invention is to produce an improved device of the type indicated above which is susceptible to various applications, among which in particular application for the production of an infrared spectrophotometer, the operation of which is reliable and efficient.
With a view to attaining this object, the invention relates to a device of the type indicated above, wherein said surface of the petal capable of adhering to the insulating layer is predisposed as a reflecting surface, designed to reflect and diffuse in all directions a beam of light incident on it when the petal is in the position at rest, and wherein over said substrate a mirror is predisposed designed to receive and reflect said beam of light when this is not intercepted by the electrostatically controlled petal, and when the latter is in its operating position, so that said device constitutes a micromirror that can be obscured by means of an electrostatically controlled microshutter.
The device thus produced has the advantage that the characteristics and the quality of the mirror do not depend on the micromachinings utilized to produce the petal.
The aforesaid mirror has a substrate which may be composed of the same surface of the substrate to which the petal adheres, or by an additional substrate applied over the substrate of the petal. The mirror may be disposed with the reflecting surface parallel to the surface of the substrate of the petal, or inclined in relation to this.
It is possible to provide a matrix arrangement of a plurality of micromirrors associated with electrostatically controlled microshutters according to the arrangement described above. A matrix of this type may, for example, be utilized advantageously in an infrared spectrophotometer, in which the micromirrors of the matrix are selected, by means of the relative microshutters, in order to select predetermined frequencies of a beam of light with dispersed chromatic components.
A further advantage of the device according to the invention resides in the fact that the petal supplied with electric voltage is never struck by the beam of light and therefore does not become nearly as hot as it would if the surface of the petal were to serve as a micromirror, thus allowing more intense beams to be modulated.
Further characteristics and advantages of the invention shall become apparent from the description below with reference to the accompanying drawings, provided purely as a non-limiting example, in which:
According to the invention, the surface 6b of the petal 6 which adheres to the insulating layer 5 in the operating condition shown in
As already shown above, it is possible to provide a linear array or a bi-dimensional matrix composed of a plurality of devices of the type shown in
Naturally, without prejudice to the principle of the finding, the constructional details and embodiments may vary widely in relation to what is described and shown purely as an example, without however departing from the scope of the present invention.
For example, a refractive or diffractive optic element may be associated with the mirror M. The reflecting surface of the petal may be provided with thin optic elements, such as binary diffractive optic elements. The mirror may also be composed of diffractive optic microridges of a height ranging from 0.2 to 2 microns.
Claims
1. Electrostatically controlled optic device with a variable operating mode, comprising:
- a fixed support including a substrate in the form of a lamina a few millimeters or centimeters thick,
- an electrode composed of a film of electrically conductive material a few tens or hundreds of nanometers thick, applied to one side of the lamina constituting the substrate,
- a dielectric or ferroelectric insulating film with a thickness ranging from 0.1 micrometers to a few tens of micrometers, applied over the film constituting said electrode, and
- a movable petal, comprising a film of electrically conductive material, with a thickness ranging from a few fractions of micron to a few microns, having only an end portion connected rigidly to said insulating film and designed to assume an operating condition, in which it adheres completely with one of its surfaces, through electrostaticity, over said insulating film when an electric voltage is applied between said electrode and said petal, and a condition at rest, curled up, towards which the petal is drawn by its own elasticity when no electric voltage is applied, and in which a predominant portion of the aforesaid surface of the petal is spaced from said insulating film,
- wherein said surface of the petal is predisposed as a reflecting surface, designed to reflect and diffuse in all directions a beam of light incident on it when the petal is in the position at rest, and
- wherein a mirror in the form of a planar reflective layer is provided as a separate element both with respect to said petal and said substrate, said mirror being fixed over said substrate on the same side thereof as said petal, so as to receive and reflect said beam of light when the beam of light is not intercepted by the electrostatically controlled petal, that is when said petal is not in its position at rest, so that said device constitutes a micromirror that can be obscured by means of an electrostatically controlled microshutter.
2. Optic device according to claim 1, wherein the mirror has a substrate composed of the same surface of the substrate to which the petal adheres.
3. Optic device according to claim 2, wherein the mirror comprises a reflecting layer, applied over the portion of the petal which adheres to the substrate.
4. Optic device according to claim 1, wherein the mirror has an additional substrate which fixes the mirror over the substrate.
5. Optic device according to claim 4, wherein said mirror comprises a reflective layer, applied over said additional substrate, and wherein said additional substrate, for example composed of silicon, is applied over said portion of the petal which is fixed to the substrate by means of interposition of a layer of heat insulating binding material, such as polyamide or epoxy resin.
6. Optic device according to claim 1, wherein the mirror has a flat reflecting surface parallel to the surface of the substrate.
7. Optic device according to claim 6, wherein the mirror is applied over the portion of the petal which is fixed to the substrate.
8. Optic device according to claim 1, wherein the mirror has a reflecting surface inclined in relation to the surface of the substrate.
9. Matrix of micromirrors which can be obscured by means of electrostatically controlled microshutters, wherein the matrix comprises a plurality of devices according to claim 1.
10. Infrared spectrophotometer comprising a matrix according to claim 9, and electronic control means to control the application of voltage to the various electrostatically controlled microshutters in order to select predetermined frequencies of a beam of light with dispersed chromatic components.
11. Optic device according to claim 1, wherein the mirror is associated with a refractive or diffractive optic element.
12. Optic device according to claim 1, wherein said reflecting surface of the petal is predisposed with thin optic elements, for example binary diffractive optic elements.
13. Optic device according to claim 1, wherein said mirror is composed of microridges of a height of 0.2 to 2 microns.
14. Optic device according to claim 1, wherein the mirror is applied over the portion of the petal which is fixed to the substrate.
15. Electrostatically controlled optic device with a variable operating mode, comprising:
- a fixed support including a substrate in the form of a lamina a few millimeters or centimeters thick,
- an electrode composed of a film of electrically conductive material a few tens or hundreds of nanometers thick, applied to one side of the lamina constituting the substrate,
- a dielectric or ferroelectric insulating film with a thickness ranging from 0.1 micrometers to a few tens of micrometers, applied over the film constituting said electrode, and
- a movable petal, comprising a film of electrically conductive material, with a thickness ranging from a few fractions of micron to a few microns, having only an end portion connected rigidly to said insulating film and designed to assume an operating condition, in which it adheres completely with one of its surfaces, through electrostaticity, over said insulating film when an electric voltage is applied between said electrode and said petal, and a condition at rest, curled up, towards which the petal is drawn by its own elasticity when no electric voltage is applied, and in which a predominant portion of the aforesaid surface of the petal is spaced from said insulating film,
- wherein said surface of the petal is predisposed as a reflecting surface, designed to reflect and diffuse in all directions a beam of light incident on it when the petal is in the position at rest, and
- wherein over said substrate a mirror is predisposed, designed to receive and reflect said beam of light when it is not intercepted by the electrostatically controlled petal, that is when said petal is in its position at rest, so that said device constitutes a micromirror that can be obscured by means of an electrostatically controlled microshutter,
- wherein the mirror has a substrate composed of the same surface of the substrate to which the petal adheres,
- wherein the mirror comprises a reflecting layer applied over the portion of the petal which adheres to the substrate.
16. Electrostatically controlled optic device with a variable operating mode, comprising:
- a fixed support including a substrate in the form of a lamina a few millimeters or centimeters thick,
- an electrode composed of a film of electrically conductive material a few tens or hundreds of nanometers thick, applied to one side of the lamina constituting the substrate,
- a dielectric or ferroelectric insulating film with a thickness ranging from 0.1 micrometers to a few tens of micrometers, applied over the film constituting said electrode, and
- a movable petal, comprising a film of electrically conductive material, with a thickness ranging from a few fractions of micron to a few microns, having only an end portion connected rigidly to said insulating film and designed to assume an operating condition, in which it adheres completely with one of its surfaces, through electrostaticity, over said insulating film when an electric voltage is applied between said electrode and said petal, and a condition at rest, curled up, towards which the petal is drawn by its own elasticity when no electric voltage is applied, and in which a predominant portion of the aforesaid surface of the petal is spaced from said insulating film,
- wherein said surface of the petal is predisposed as a reflecting surface, designed to reflect and diffuse in all directions a beam of light incident on it when the petal is in the position at rest, and
- wherein over said substrate a mirror is predisposed, designed to receive and reflect said beam of light when it is not intercepted by the electrostatically controlled petal, that is when said petal is in its position at rest, so that said device constitutes a micromirror that can be obscured by means of an electrostatically controlled microshutter,
- wherein said mirror is composed of microridges of a height of 0.2 to 2 microns.
3989357 | November 2, 1976 | Kalt |
5305083 | April 19, 1994 | Marianik et al. |
5629565 | May 13, 1997 | Schlaak et al. |
5959763 | September 28, 1999 | Bozler et al. |
6236491 | May 22, 2001 | Goodwin-Johansson |
6396620 | May 28, 2002 | Goodwin-Johansson |
6731492 | May 4, 2004 | Goodwin-Johansson |
20040046123 | March 11, 2004 | Dausch |
1 008 885 | November 1999 | EP |
1008885 | June 2000 | EP |
1241508 | September 2002 | EP |
1318426 | June 2003 | EP |
Type: Grant
Filed: Dec 6, 2002
Date of Patent: May 3, 2005
Patent Publication Number: 20030117733
Assignee: C.R.F. Societa Consortile per Azioni (Orbassano)
Inventors: Marco Pizzi (Turin), Valerian Koniachkine (Novosibisk)
Primary Examiner: David Porta
Assistant Examiner: Christine Sung
Attorney: Brooks Kushman P.C.
Application Number: 10/313,620